1. Technical Field
The present disclosure relates to voice coil motors.
2. Description of Related Art
Voice coil motors (VCMs) are widely used, for example, as lens actuators in camera modules. Camera modules are becoming progressively more miniaturized over time, and thus VCMs are correspondingly being required to be made smaller and smaller.
A typical VCM includes a stationary magnetic field generator, a movable magnetic field generator, at least one elastic member attached to the stationary magnetic field generator, and a case receiving all the above-mentioned elements therein. The movable magnetic field generator has coils of wire wrapped around a periphery thereof, and, for example, can have lenses received therein. The movable magnetic field generator together with the lenses can be moved by the magnetic field generated by the stationary magnetic field generator. The case has a top sheet. The movable magnetic field generator usually has a plurality of pins formed thereon. The pins engage with the elastic member and extend through the elastic member to face the top sheet of the case. The elastic member provides reverting force on the movable magnetic field generator. When the pins contact the top sheet, it means that the movable magnetic field generator has moved as far as it can go.
However, in the case of a highly miniaturized VCM, it is difficult to make the VCM, and the VCM may not be able to perform satisfactorily.
What is needed, therefore, is a voice coil motor which can overcome the above shortcomings.